The Z4 has standard BMW Assist, which uses a global positioning satellite (GPS) receiver and a cellular system to remotely unlock your doors if you lock your keys in, help track down your vehicle if it’s stolen or send emergency personnel to the scene if any airbags deploy. The Boxster doesn’t offer a GPS response system, only a navigation computer with no live response for emergencies, so if you’re involved in an accident and you’re incapacitated help may not come as quickly.
Both the Z4 and the Boxster have standard driver and passenger frontal airbags, front side-impact airbags, driver and front passenger knee airbags, side-impact head airbags, front seatbelt pretensioners, four-wheel antilock brakes, traction control, electronic stability systems to prevent skidding, daytime running lights and available rear parking sensors.
The Z4’s corrosion warranty is 2 years longer than the Boxster’s (12 vs. 10 years).
BMW pays for scheduled maintenance on the Z4 for 4 years and 50,000 miles. BMW will pay for oil changes, lubrication and any other required maintenance. Porsche doesn’t pay scheduled maintenance for the Boxster.
There are over 74 percent more BMW dealers than there are Porsche dealers, which makes it much easier should you ever need service under the Z4’s warranty.
The Z4 has more powerful engines than the Boxster:
Horsepower |
Torque |
|
Z4 sDrive28i 2.0 turbo 4 cyl. |
240 HP |
260 lbs.-ft. |
Z4 sDrive35i 3.0 turbo 6 cyl. |
300 HP |
300 lbs.-ft. |
Z4 sDrive35is 3.0 turbo 6 cyl. |
335 HP |
332 lbs.-ft. |
Boxster 2.7 DOHC 6 cyl. |
265 HP |
207 lbs.-ft. |
Boxster S 3.4 DOHC 6 cyl. |
315 HP |
266 lbs.-ft. |
Boxster GTS 3.4 DOHC 6 cyl. |
330 HP |
273 lbs.-ft. |
As tested in Road & Track the Z4 sDrive35is 3.0 turbo 6 cyl. is faster than the Boxster S 6 cyl. (automatics tested):
Z4 |
Boxster |
|
Zero to 60 MPH |
4.4 sec |
4.5 sec |
Zero to 100 MPH |
10.6 sec |
11.3 sec |
Quarter Mile |
12.9 sec |
13 sec |
Speed in 1/4 Mile |
109.9 MPH |
107.4 MPH |
On the EPA test cycle the Z4 gets better fuel mileage than the Boxster:
Z4 |
Boxster |
|||
4 cyl./Manual |
22 city/34 hwy |
20 city/30 hwy |
6 cyl. |
|
cyl./Manual |
n/a |
20 city/28 hwy |
||
4 cyl./Auto |
22 city/33 hwy |
22 city/32 hwy |
6 cyl. |
|
6 cyl./Auto |
n/a |
22 city/31 hwy |
||
6 cyl. /Auto |
n/a |
21 city/30 hwy |
For better stopping power the Z4’s standard brake rotors are larger than those on the Boxster:
Z4 |
Boxster |
|
Front Rotors |
13 inches |
12.4 inches |
The Z4’s optional 255/30R19 rear tires provide better handling because they have a lower 30 series profile (height to width ratio) that provides a stiffer sidewall than the Boxster’s optional 35 series tires.
Changing a flat tire near traffic can be dangerous and inconvenient. The run-flat tires standard on the Z4 can be driven up to 50 miles without any air pressure, allowing you to drive to a service station for a repair. The Boxster doesn’t offer run-flat tires.
The Z4’s front to rear weight distribution is more even (49.4% to 50.6%) than the Boxster’s (45% to 55%). This gives the Z4 more stable handling and braking.
For better maneuverability, the Z4’s turning circle is .9 feet tighter than the Boxster’s (35.1 feet vs. 36 feet).
The Z4 is 5.3 inches shorter than the Boxster, making the Z4 easier to handle, maneuver and park in tight spaces.
The Z4’s standard power retractable hardtop allows a seamless transition from an open car, to a completely sealed coupe. The Boxster doesn’t offer a retractable hardtop.
As tested by Road & Track, the interior of the Z4 sDrive35i is quieter than the Boxster S:
Z4 |
Boxster |
|
At idle |
46 dB |
49 dB |
Full-Throttle |
76 dB |
85 dB |
If the windows are left down on the Z4 the driver can raise them all using the key in the outside lock cylinder or the keyless remote; on a hot day the driver can lower the windows. The driver of the Boxster can’t use the remote to operate the windows.
The Z4’s rain-sensitive wipers adjust their speed and turn on and off automatically based on the amount of rainfall on the windshield. This allows the driver to concentrate on driving without constantly adjusting the wipers. The Boxster’s standard manually variable intermittent wipers have to be constantly adjusted.
The Z4 has a standard dual zone air conditioning allows the driver and front passenger to choose two completely different temperatures so people with different temperature preferences won’t have to compromise. This makes both the driver and front passenger as comfortable as possible. Dual zone air conditioning costs extra on the Boxster.
Intellichoice estimates that five-year ownership costs (depreciation, financing, insurance, fuel, fees, repairs and maintenance) for the BMW Z4 will be $6724 to $7927 less than for the Porsche Boxster.
Intellichoice recognized the BMW Z4 as a “Best Value of the Year” for the 2015 model year. The Porsche Boxster didn't win any recognition from Intellichoice.
© 1991-2016 Advanta-STAR Automotive Research. All rights reserved.
Who We Are
Click here
to view the disclaimers, limitations and notices about EPA fuel mileage, crash tests, coprights, trademarks, and other issues.